From some angles, it looks like an alien airship is glowing, suspended in a galaxy of clear tentacles.

From other vantage points, the kinetic artwork appears to be a relatively shallow curtain.

Approach - or better yet, step into - Jesús Rafael Soto's "Houston Penetrable" and you realize it is bigger than some houses, filling 2,600 square feet with 24,000 strands of plastic tubing that dangle 27 feet from a grid near the ceiling.

About the size of oxygen-machine tubes, the strands are slightly cool and soft to the touch. You can let them cling or use your hands to needle through as light bounces above like the rays of a hundred magic suns. High up, many tubes have been hand-painted yellow with water-based silk-screen ink, creating the illusion of the floating ellipse visible from the outside.

The Museum of Fine Arts, Houston unveiled Soto's final and most ambitious project last week in its Caroline Wiess Law Building, which was designed by the great modernist Ludwig Mies van der Rohe. The pairing has taken a decade.

"This is a huge achievement. There are very few museums in the world that will embark on something like this," director Gary Tinterow said.

Curator Mari Carmen Ramírez, who initiated the project, was ebullient. "It's like Mies and Soto were made for each other," she said. She loves how sunlight from the building's foyer plays across the artwork's bottom half.

One of the most important artists to emerge from Latin America in the last half of the 20th century, Soto, who died in 2005, worked with space in the same way his friend Carlos Cruz-Diez attunes us to color or James Turrell awakens our senses to light.

Soto, who studied at the School of Fine Arts in his native Venezuela, moved to Paris in 1950 and joined a group who thought painting was passé.

"They wanted to introduce movement to art," Ramírez said. "It's an essential part of human life, but how do you reproduce that in a static medium? In the Renaissance, you had artists using different approaches to perspective. In the Baroque period, it was illusionism."

Some of Soto's friends, including Jean Tinguely and Alexander Calder, made mechanical contraptions - kinetic art - with moving parts. But Soto had a more radical idea that required a viewer to complete it: His works moved only through human perception.

Ramírez has displayed eight earlier works to illustrate how that idea evolved. With 1956's "Untitled (Kinetic Structure of Geometric Elements)," you can appreciate how simply Soto achieved his magic. It juxtaposes two striped panes of clear Plexiglas that appear to vibrate as you walk by. Wires protrude from densely painted canvases in his more complex Baroque series. Later, he dialed back to cleaner geometric forms based on squares.

"For him, the square is the most important shape; it's a man-made shape that does not exist in nature," Ramírez said. "Cuadrados virtuales," a 1974 work, doesn't have any squares, but selectively painted metal and nylon wires create that illusion when you're standing in the sweet spot.

Soto created his first Penetrable in 1967, eventually producing about 30. Most were temporary outdoor sculptures, and they all utilized existing blue, yellow or clear industrial PVC tubing. They became a signature.

"The 'Penetrable' isn't even a work," Soto wrote. "It's more an idea of space that can materialize in any situation and at any scale. If it were possible, you could even make it cover the entire planet. The important thing is to show that space is fluid and full because it has always been considered a place where things can be put more than as a primal, universal value."

The museum commissioned the work after the much smaller "Yellow Penetrable" proved popular during its landmark 2004 exhibition "Inverted Utopias: Avant-Garde Art in Latin America." Assuming she'd get an outdoor sculpture, Ramírez showed the artist around the campus to choose a site. "He became very enthusiastic. He really wanted to do something for Houston. He had a good experience here," she said.

A few months later she had plans for a work at the Cullen Sculpture Garden. But the scale and proportions were too large, so they started over, eventually settling on the Cullinan Hall site. It was still unusually large, but the grid system was well-established. "That seemed to be a very simple proposition 10 years ago," Ramírez said.

But Soto, who was in his 80s and had cancer, died less than a month after delivering the computer renderings and drawings. And unlike the previous Penetrables, this one was to be painted, with no more than four strands in each quadrant alike.

After scouring the U.S. unsuccessfully for a fabricator, Ramírez found Soto's original architect, Paolo Carrozzino, and grid-system producer, Walter Pellevoisin. Collaborating with Atelier Soto, the artist's Paris studio, they oversaw a team of artisans and ironworkers in France who created the components. That took about five years.

"Houston Penetrable" arrived in many 15-foot crates last summer. Each strand was numbered, to be looped in batches of 100 through holes in 240 square panels that fit into the grid.

"There's over 8 million inches of tubes in here. If you equate that to feet, that is 534 Empire State Buildings or 74 Golden Gate Bridges," said the museum's chief preparator, Dale Benson. "You can imagine the daunting task, about two months, with six or seven of us in an off-site warehouse, just stringing the tubes through all the individual holes, keeping our fingers crossed that we got it right and it was going to look like a yellow circle at the end."

The 'Penetrable's' weight - about 7 tons - posed even greater issues. It became a catalyst for major renovations in the building, including a re-engineered ceiling with another 8 tons of supportive steel, plus new LED lighting and better cabling for video projections.

After Sept. 1, "Houston Penetrable" will go into specially designed crates until the museum can display it again. Tinterow and Ramírez hope to make it a frequent summer attraction. "It's been an amazing journey. Everybody at the museum has participated," Ramírez said.

She doesn't know why Soto decided to create the illusion of the ellipse for his final Penetrable, although she suspects he was thinking about the end of his life. "One of the things that becomes really clear... He spent so much time trying to get away from painting, but this is a painting. There's a pictorial principle here," she said.

"Houston Penetrable" can be a spiritual or a playful experience, depending on your mood. But from any perspective, it's an awesome addition to the collection.